In the past, the general practice of surgeons or other medical practioners using hypodermic syringes has been to transfer an injection solution to a syringe from a glass vial using a broad channelled needle attached to the syringe body. Following transfer, this broad channelled needle has been removed from the syringe and replaced with a narrower channelled hypodermic needle suitable for injecting the solution into the patient. It will be appreciated that this past practice has necessitated the use of a number of separate components. Furthermore, as solution transfer for injecting into humans requires scrupulous sterilizing of components, this previous practice has required separate sterilizing measures to be taken at each step.
To avoid the problems of such transfer, it has been previously proposed to provide ampoules or vials holding a single dose. These single dose vials have been adapted to fit like cartridges into a syringe body onto which can be fitted a hypodermic needle. Such unit dose vials are normally manufactured from glass and sealed with a rubber membrane and the vial is punctured by attaching to the syringe body a double sided needle.
An alternative arrangement is disclosed in Australian patent 556,483 where a unit dose container is described made from a thermoplastic material which is adapted to be opened and co-operatively engaged directly onto a needle fitting on a syringe to which it is desired to transfer injection fluid. Whilst this patent describes a satisfactory arrangement for use with a standard friction fit needle fitting such as a luer slip fitting, it does not deal with the problems associated with syringes utilizing screw thread engagement systems such as the luer lock system.
It is an object of the present invention to provide a container suitable for use with a syringe having a screw thread engagement fitting to facilitate more secure, easier and more convenient transfer of an injection solution to a syringe which has a screw thread engagement fitting than has hitherto been possible.